Technical Field
Embodiments of the invention relate generally to vehicles. Certain embodiments relate to systems and methods for controlling a vehicle.
Discussion of Art
In some vehicles, electrically motorized wheels propel or retard the vehicle. In particular a large horsepower diesel engine may be used with an alternator, a traction inverter, and wheel drive assemblies housed within the rear tires of the vehicle. In operation, a diesel engine drives an alternator, which powers the traction inverter. The traction inverter includes semiconductor power switches that commutate the alternator output current to provide electrical power to electric drive motors, e.g., AC traction motors, of the wheel drive assemblies, which transform the electrical power back into mechanical power to drive the wheels and propel the vehicle.
The traction motors provide the tractive power to propel a vehicle. The traction motors provide a braking force for controlling speed or for slowing the vehicle. This is commonly referred to as dynamic braking. Simply stated, when a traction motor is not needed to provide motive force, it can be reconfigured so that the motor operates as a power generator. So configured, the traction motor generates electric energy which has the effect of slowing the vehicle.
Certain vehicles may also be equipped with a service brake that is manually actuatable by an operator to provide a friction braking force to one or more wheels of the vehicle to stop or slow the vehicle. For example, existing service brakes typically require manual actuation by an operator of the vehicle, such as by depressing a pedal on the floor of the vehicle, which causes pressure to be applied to brake pads to slow or stop the vehicle.
In view of the above, there may be a need for a system and method which differs from those systems that are currently available.